The overview tab should be the first one you see when you open the reports on a tracker and should contain the following:
Total hits - the total number of visitors your site has seen since the tracker was placed.
Unique hits - the number of those hits that are marked unique. Unique visitors are tracked using a triple layer check that looks for browser, IP address, and cookie. This is to minimize multiple unique hits from one person.
date created - the date the tracker was created
Tracker information - the information that tells you what kind of tracker you have selected, as well as the information on the tracker and the overview of the tracker's performance.
Tracker Type - link, pixel, or custom link
Tracking Pixel - an embeddable code for the tracking pixel that will track visits to the page as opposed to link clicks.
Overview - a graph that shows you the number of times the tracker has been activated since its inception, or within the time frame specified.